1. Field of Invention
The present invention relates to an integrated device with AC (alternating current) to DC (direct current) conversion function, and an integrated circuit using the integrated device.
2. Description of Related Art
In an electronic circuit, it is often required to convert an AC voltage to a DC voltage and supply the latter to an integrated circuit. As shown in FIG. 1, conventionally, a bridge rectifier 10 is used for such AC to DC conversion. The bridge rectifier 10 includes resistors R1 and R2 to lower the AC voltage level, and four diodes 12, 14, 16, and 18 to rectify the AC voltage. A resistor R further reduces the rectified DC voltage, and a Zener diode Z is provided to clamp the upper limit of the DC voltage; the DC voltage is supplied to a subsequent circuit 50. The subsequent circuit 50 can be any circuit operating under low DC voltage, such as a photo sensor, an LED control circuit, etc.
Conventionally, the rectifier 10 must be formed by discrete diodes, which can not be integrated with other electronic devices to become an integrated circuit. Such disadvantage should be improved.
Accordingly, the present invention provides an integrated device with AC to DC conversion function, which can be integrated with a circuit operating under low DC voltage to become an integrated circuit. The present invention also provides an integrated circuit using the device.